Cellulose-ether composition



Patented Sept. 8, 1925 UNITED STATES PATENT OFFICE STEWART I. CARROLL, O1 ROCHESTER, NEW YORK, ASBIGNOR TO EASTMAN KODAK COKI'ANY, OF ROCHESTER, NEW YORK, A CORPORATION 01' NEW YORK.

cantunosn'mrnan .courosrrron.

Io Drawin To all whom it may concern:

Be it known that I, STEWART J. CARROLL, a citizen of the United States of America, residing at Rochester, in the county ofMon- 5 roe and State of New York, have invented certain new and useful Improvements in Cellulose-Ether Compositions, ofwhich the fol lowing is a full, clear, and exact specification.

This invention relates to solvents for making strong solutions of cellulose ether and also relates to the cellulose ether compositions roduced by the aid of such solvents. One 0 ject of my invention is to provide a 18 solvent which will dissolve such large proportions of cellulose ethers that thick or viscous flowable solutions may be obtained for use in plastic and film making arts. Another object of'my invention is to pro- 20 vide a cellulose ether solution which may be manufactured into strong, flexible, transparent films on the machines and by the methods nowin use. Other objects will hereinafter appear. 7

In U. S. Patent No. 1,188,376, Lilienfeld,

June 20, 1916, there are disclosed a series v of alkyl ethers of cellulose. Certainof these are practically insoluble in water, and my invention relates, but is not limited, to the 30 others having that property. While cellulose ethers form thin solutions in the lower monohydroxy aliphatic alcohols or 1n resorcinol diacetate, it has been found that such single solvents by themselves do not dissolve a sufficient proportion of the ethers to make a desirably thick fiowable composition or dope, such as may be used in the manufacture of photographic film base by customary methods or in the'other plastic 40 arts.

I have discovered that an adequately strong by mixing resorcinol diacetate wi one or more of the lower monohydroxy aliphatic alcohols. Inotherwords, I have discovered that mixtures of these ingredients have a greater solvent action on cellulose others than similar weights of such ingredients when employed by themselves. By lower monohydroxy aliphatic alcohols, I -means those having less than sixcarbon atoms. While the ingredients may be mixed in widely varying proportions it is noted, by

- camphor, etc.

and useful solvent may be prepared Application fled February 24, 1928. Serial No. 621,089.

way of example, that a particularly useful composition can be prepared by mixing eq ual arts by weight of resorcinol diacetate w1th t e aliphatic alcohol, say methyl alcohol. In the preferred form of my invention, I dissolve 1 part by weight of the cellulose ether, say water-insoluble ethyl cellulose, in from 5 to 7 parts by weight of the solvent mixture. The ingredients by. themselves are not sufliciently powerful to make properly flowable solutions of this strength. Of course, the proportion of mixed solvent or the proportion of the volatile ingredients may be increased to adapt the com osition to the lacquering art, as will be un erstood by skilled persons.

Other substanceswhich im art additional suppleness, or incombustibi ity, or other qualities, to the filmmay also be added to the dope, such, for instance, as triphenyl or tricresyl phosphate, monochlornaphthalene,

The ingredients are of the ordinary commercial type and sufiiciently purified for the process of film manufacture, so as to give a dope yielding films having the proper relative freedom'from color. The viscous-flowable dope above described can be used in connection with the usual film-forming apparatus without the necemity of expensive alterations in the latter.

In the formation of a film by the evaporation of the volatile ingredients from the hereinabove described com itions, a considerable amount of resorcmol diacetate remains behind, because of its relatively low volatility. It imparts useful plastifying and other propertles to the film, which is normall flexible and transparent. More over, fi ms containing it show remarkable flexibility after undergoing a continuous heating test at 65 C. for. twelve weeks.

'Havin thus described my invention, what I c aim as new and desire to secure by Letters Patent is:

1. A composition of matter comprising cellulose ether and resorcinol diacetate, the ingredients being homogeneously mixed in unprecipitated form. V

2. A composition of matter comprisin cellulose ether dissolved in a mixture 0 resorcinol diacetate andv alower monohy- 105 droxy aliphatic alcohol.

3. A composition of matter comprisin parts by weight of water-insoluble ethyl ll cellulose ether dissolved in a mixture 0 cellulose, 7 parts of resorcinol diacetate and resorcinol diacetate and methyl alcohol. 7 arts of meth 1 alcohol.

4. A flowable composition comprising 1 As an article of manufacture, a film part of cellulose ether dissolved in from 5 comprising cellulose ether and resorcinol to 7 parts by weight of a mixture of rediacetate. sorcinol diacetate and alowermonohydroxy 8. As an article of manufacture, a tough aliphatic alcohol. flexible transparent film comprising water- 5. A composition of matter comprisin insoluble ethyl cellulose and resorcinol dicellulose ether dissolved in a mixture 0 acetate. substantially equal parts by weight of re- Signed at Rochester, New York this 19th 25 sorcinol diacetate and a lower monohydroxy day of February 1923. aliphatic alcohol.

6. A composition of matter comprising 2 STEWART J. CARROLL. 

